Nuclear Weapons and Nuclear Strategy

Introduction

Nuclear weapons and nuclear strategy occupy a central position in international security because of the extraordinary destructive capability of nuclear weapons and their implications for deterrence, strategic stability, arms control and international politics.

Nuclear strategy concerns how states develop, deploy and communicate nuclear capabilities and how they seek to deter adversaries, protect national interests and manage escalation.

Nuclear weapons have influenced international relations since their development during the Second World War and became especially important during the Cold War.

Nuclear Weapons

Nuclear weapon is a weapon that derives explosive energy from nuclear reactions.

There are two basic physical mechanisms:

Fission weapon releases energy through the splitting of heavy atomic nuclei.

Thermonuclear weapon uses a combination of nuclear processes and can produce much greater explosive yields than basic fission weapons.

Nuclear yield refers to the explosive energy released by a nuclear weapon, commonly expressed in equivalent amounts of TNT.

Nuclear Deterrence

Nuclear deterrence is the use of nuclear capabilities to discourage an adversary from taking actions considered unacceptable.

The central logic is that the expected consequences of nuclear retaliation make certain actions too costly.

Nuclear deterrence depends heavily on:

• Survivable nuclear forces
• Credible retaliation
• Command and control
• Communication
• Strategic signalling
• Second-strike capability

Second-Strike Capability

Second-strike capability is the ability of a state to launch a retaliatory nuclear attack after absorbing an opponent’s initial nuclear strike.

It is central to strategic stability.

A state with a secure second-strike capability cannot easily be disarmed through a surprise first strike.

Nuclear Triad

A nuclear triad is a strategic force structure consisting of three major delivery components:

1. Land-based ballistic missiles
2. Submarine-launched ballistic missiles
3. Strategic bombers

The purpose of the triad is to diversify delivery systems and strengthen survivability.

Ballistic missile follows a trajectory influenced substantially by gravity after powered flight.

Submarine-launched ballistic missile (SLBM) is a ballistic missile launched from a submarine.

Strategic bomber is a long-range aircraft designed to deliver strategic weapons.

Nuclear Posture

Nuclear posture refers to a state’s overall nuclear strategy, force structure, deployment patterns, doctrine and declared policy.

No-first-use (NFU) is a policy under which a state declares that it will not use nuclear weapons first.

First-use policy allows for the possibility of initiating nuclear use under specified circumstances.

Nuclear ambiguity occurs when a state deliberately avoids clearly defining the circumstances under which it would use nuclear weapons.

Nuclear Doctrine

Nuclear doctrine consists of the principles governing the role, purpose and potential use of nuclear weapons.

A doctrine may address:

• Deterrence
• Retaliation
• First use
• Second strike
• Escalation
• Command and control
• Targeting
• Force survivability

Counterforce and Countervalue

Counterforce targeting focuses on an adversary’s military forces and strategic capabilities.

Potential targets include:

• Missile sites
• Nuclear facilities
• Military bases
• Command-and-control infrastructure

Countervalue targeting focuses on assets associated with the opponent’s broader society and economic capacity.

The distinction is important in discussions of nuclear strategy and targeting doctrine.

Nuclear Command and Control

Nuclear command and control (NC2) refers to systems and procedures governing authorization, communication and control of nuclear forces.

A credible nuclear force requires:

• Secure communications
• Reliable early warning
• Political authorization
• Protection against unauthorized use
• Clear command structures

Permissive action link (PAL) is a security mechanism designed to prevent unauthorized use of nuclear weapons.

Early Warning

Early-warning systems detect potential missile launches or other indicators of nuclear attack.

Their purpose is to provide decision-makers with sufficient information and time to assess whether an attack is occurring.

False alarm occurs when a system incorrectly indicates an incoming attack.

False alarms are significant because misinterpretation can create escalation risks.

Strategic Stability

Strategic stability refers broadly to conditions in which states have reduced incentives to initiate a major strategic attack.

Two related concepts are:

Crisis stability: Whether leaders have incentives to strike first during a crisis.

Arms-race stability: Whether changes in military capabilities are likely to create incentives for destabilizing competition.

Mutually Assured Destruction

Mutually Assured Destruction (MAD) describes a condition in which opposing nuclear powers possess survivable forces capable of inflicting catastrophic destruction after an initial attack.

The concept became particularly associated with US-Soviet strategic relations during the Cold War.

Nuclear Arms Race

Nuclear arms race occurs when states compete to improve the quantity, quality, survivability or effectiveness of their nuclear capabilities.

Competition may involve:

• Warhead numbers
• Missile accuracy
• Delivery systems
• Submarines
• Missile defences
• Early-warning systems
• Command and control

Nuclear Sharing

Nuclear sharing refers to arrangements under which nuclear-armed states cooperate with allies concerning nuclear deterrence and, in some arrangements, delivery capabilities.

The concept is particularly associated with NATO.

Extended Nuclear Deterrence

Extended nuclear deterrence occurs when a nuclear-armed state seeks to deter attacks against allies by extending its nuclear deterrent commitment to them.

This can influence alliance politics and the nuclear policies of non-nuclear allies.

Nuclear Strategy and Escalation

Nuclear strategy is closely connected with escalation.

Escalation can involve movement from conventional conflict to nuclear signalling or nuclear use.

Nuclear threshold refers to the circumstances under which nuclear weapons might be considered for use.

Escalation control involves attempts to prevent conflict from moving to increasingly destructive levels.

Key Distinctions

Key Terms at a Glance

Nuclear weapon: Weapon deriving explosive energy from nuclear reactions.

Nuclear deterrence: Deterrence based on nuclear capabilities.

Second-strike capability: Ability to retaliate after a nuclear attack.

Nuclear triad: Land, sea and air-based strategic nuclear forces.

Nuclear posture: Overall structure and policy of nuclear forces.

Nuclear doctrine: Principles governing nuclear strategy.

No-first-use: Policy rejecting first use of nuclear weapons.

Counterforce: Targeting an opponent’s military capabilities.

Countervalue: Targeting an opponent’s broader societal assets.

Nuclear command and control: Systems governing authorization and control.

Strategic stability: Conditions that reduce incentives for strategic attack.

Nuclear arms race: Competitive development of nuclear capabilities.

Related Glossaries

This topic connects directly with 3.1 Power in International Relations, 3.2 Hard Power, Soft Power and Smart Power, 9.3 Security Dilemma and Strategic Stability, 9.4 Deterrence, Compellence and Containment, 11.2 Nuclear Deterrence and Strategic Stability, 11.3 Nuclear Proliferation and Non-Proliferation, and 11.4 Nuclear Disarmament and Arms Control.